Carbonate compounds are currently used as electrolyte solvents for non-aqueous batteries containing electrodes made from alkali metals, alkaline earth metals, or compounds comprising these metals, for example lithium ion batteries. Current lithium ion battery electrolyte solvents typically contain one or more linear carbonates, such as ethyl methyl carbonate, dimethyl carbonate, or diethylcarbonate; and a cyclic carbonate, such as ethylene carbonate. However, at cathode potentials above 4.4 V these electrolyte solvents can decompose, which can result in a loss of battery performance. Additionally, there are safety concerns with the use of these electrolyte solvents because of their low boiling point and high flammability.
Various approaches have been investigated to overcome the limitations of commonly used non-aqueous electrolyte solvents. For example, additives, such as cyclic carboxylic acid anhydrides, have been used in combination with the currently used electrolyte solvents (see, for example, Jeon et al. U.S. Patent Application Publication No. 2010/0273064 A1). Additionally, various fluorinated carboxylic acid ester electrolyte solvents have been investigated for use in lithium ion batteries (see, for example, Nakamura et al in JP 4/328,915-B2, JP 3/444,607-B2, and U.S. Pat. No. 8,097,368). Although these electrolyte solvents can be used in lithium ion batteries having high potential cathodes, such as the 4 V spinel LiMn2O4 cathode, cycling performance can be limited, particularly at high temperatures.
Despite the efforts in the art as described above, a need remains for electrolyte solvents, and compositions thereof, that will have improved cycling performance at high temperature when used in a lithium ion battery, particularly such a battery that operates with a high potential cathode (i.e. up to about 5 V).